Based on the observations made in 9 experimental plots in Jiangsu Province during the seasons 1982-1983 and 1983-1984,effective accumulated temperature (EAT) models are established for leaf rank of winter wheat. The models show that 85.5℃ and 81.8℃ of EAT are Ineeded for a single leaf to form respectively for winter wheat species ‘Jinan 13’ and ‘Yangmai 4’. The relationship between tiller rank and correspondent EAT after emergence of seedling is found to be cubic-parabolic; models giving total number of stalks and tillers per unit area are developed with respect to EAT.Contribution to the yield by various tillers in the tiller rank is analysed and the effect of EAT on the formation of stalks, leaves and biomass is finally discussed.